In a parade square,
47 of the students wore ties. After 20 students who wore ties entered the parade square, the percentage of students who wore ties increased to 75%. How many students in the parade square did not wear ties?
| |
Wore ties |
Did not wear ties |
| Before |
4x1 =
4 u |
3x1 =
3 u |
| Change |
+ 20 |
|
| After |
3x3 =
9 u |
1x3 =
3 u |
75% =
75100 =
34The number of students who did not wear ties remains unchanged. LCM of 3 and 1 is 3.
Number of students who wore ties and left
= 9 u - 4 u
= 5 u
5 u = 20
1 u = 20 ÷ 5 = 4
Number of students who did not wear ties
= 3 u
= 3 x 4
= 12
Answer(s): 12
